OSHA requirements are set by statute, standards and regulations. Our interpretation letters explain these requirements and how they apply to particular circumstances, but they cannot create additional employer obligations. This letter constitutes OSHA's interpretation of the requirements discussed. Note that our enforcement guidance may be affected by changes to OSHA rules. Also, from time to time we update our guidance in response to new information. To keep apprised of such developments, you can consult OSHA's website at http://www.osha.gov.

This is in response to your letter of November 20, 1997, addressed to Roy Gurnham, Occupational Safety and Health Administration (OSHA), in which you state that 29 CFR 1926.451(c)(1)(ii) tying or guying of supported scaffolds is more restrictive than necessary.

In your letter, you state that using intervals not greater [than] 26 feet is unnecessarily restrictive when constructing scaffolds wider than 5 feet. In the example you pose, the first tie would be at 40' and the intermediate ties at each point 26' above the first point. Thus the intermediate tie, guy or stand-off brace requirement is more restrictive than for the bottom and top tie, guy or stand-off brace. You state that this defeats the purpose of the increased base design. You suggest that OSHA allow intermediate ties, guys and standoff braces to be installed at maximum intervals of 4:1 throughout entire scaffold height.

We note that 1926.451(c)(1)(ii) is consistent with the most recent wording in ANSI A10.8-1988 (American National Standards Institute, Inc. Scaffolding-Safety Requirements). The ANSI standard calls for intermediate ties at 26 feet in sections 8.13 (Tube and Coupler Scaffolds), 9.11 (System Scaffolds) and 10.9 Fabricated Tubular Frame Scaffolds. Section 10.9 states: "The running scaffold shall be tied to the wall or structure when the height exceeds four times the minimum scaffold dimension. The first vertical and longitudinal tie shall be placed [at the point where the height reaches 4 times the minimum base dimension]. Vertical ties shall be repeated at intervals not greater than 26 feet. The top tie shall be placed no lower than four times the base dimension from the top of the scaffold. Longitudinal ties shall be placed at each end and at intervals not greater than 30 feet. Ties shall be installed to prevent the scaffold from tipping into or away from the wall or structure."

Section 1926.451(c)(1)(ii) maximizes the stability of scaffolds by giving more rigidity to the center of the structure. We are in the process of reviewing Subpart L and will be reopening it for several issues. We will consider including the issue that you raised in the reopening of the Subpart L record.

If you require any further assistance, please do not hesitate to contact us again by writing to: Directorate of Construction - OSHA Office of Construction Standards and Compliance Assistance, Rm. N3621, 200 Constitution Avenue, N.W., Washington, D.C. 20210.